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Wanted, Valve springs for Self Centring!!!!
nitram38 - 25/5/06 at 09:06 AM

I have tried 45lb pressure in my front tyres and the max castor I can get is only 3 degrees.
I have a titan steering rack and I would rather go down the spring return route rather than the toe out one.
I only have a gap of 40mm for the springs and the outside dia of my rack is 22.3mm.
Anyone have some springs that will fit?
My test is in 4 weeks.


zxrlocost - 25/5/06 at 09:19 AM

ill have a look tonight mate

chris


tom_loughlin - 25/5/06 at 09:51 AM

If you let me know sizes of springs, I might have some, i have just disected my cvh, and still have the springs.
let me know if theyre any use.

Tom


nitram38 - 25/5/06 at 10:30 AM

Cheers chaps!

They need to be 40mm from end to end and be able to go on a rod 22.3mm in dia.
They also need to be quite light as I only have 40mm commpression space.


gary gsx - 25/5/06 at 05:00 PM

Got an old 1.6 pinto head at work thats going scrap any good let me know just down the road from mitcham

Gary


nitram38 - 25/5/06 at 08:59 PM

Tom has kindly offered me the correct springs........thanks again Tom.

Those who have used this method, how much harder is your wheel to turn and how much lock did you lose?


nitram38 - 30/5/06 at 12:43 PM

I have decided to rebuild the top wishbones and increase the castor to 7 degrees.
The springs from Tom will be a back up in case the modified bones do not work. (not recieved them yet, perhaps tomorrows post).
Will update you when they are fitted and aligned (again!!!!!!)


nitram38 - 2/6/06 at 01:50 PM

Update..............success!!!!!!!

Remade the top bones on Thursday. Only took 2 Hrs. Dropped them off into the powder coaters.
Picked them up at noon today and remounted them.
Drove the car ............centers easily and without making the steering heavy.
Moved them back 30mm from vertical. Gives me about 7-8 degrees of castor. (distance between bone centers is 236mm)
I still need to adjust camber and tracking again. (probably not much). I need a day to do it on my 4 wheel tracking machine, as I am working nights.
By close of play Monday, car should be set up and finished!!!!!!!!!!

[Edited on 2/6/2006 by nitram38]


David Jenkins - 2/6/06 at 01:59 PM

People come out with all these bright ideas for getting the car to self-centre for the SVA test - but when you do the job properly (as you have) then everything becomes so much easier!

Some folks seem to forget that this requirement is a safety issue - if you're going along and let go the wheel, it's reassuring to know that the car will try to carry straight on. I should add that I've driven a car made by a major manufacturer that used to go to full lock if you held the wheel loosely and accelerated!

David

[Edited on 2/6/06 by David Jenkins]


nitram38 - 2/6/06 at 02:05 PM

David, although mine is not a 7 car, in theory, everyone with a 7 must be able to get the car to self center?
My car has no weight over the front as it is rear engined, if that makes a difference?

Martin


David Jenkins - 2/6/06 at 02:08 PM

I was very lucky, in that this topic was hot when I was making my top bones - I set the end about 22mm further back, which appears to be about right for my car. It will start to centre the steering without any difficulty, while still being light and easy to drive.

David


nitram38 - 2/6/06 at 02:33 PM

The distance you set the top bones back depends on the distance between the top and bottom ball joint centers.
Mine is 236mm, so 7 degrees was 28.8mm.
If your bone centers are closer than mine then the bone change will be shorter to give 7 degrees.
I adjusted them to 30mm. on paper that this gives 7.24 degrees castor on my setup.
I will measure it with a castor gauge on Monday.
Hopefully, a few other builders will take this discussion on board and save themselves problems later.

[Edited on 2/6/2006 by nitram38]